Method for preventing spills resulting from pipeline failures

ABSTRACT

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline includes an upstream portion of the pipeline supplying a flow of fluid material, a crossing portion of the pipeline receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline, the downstream portion, a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion, and a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the valve blocking the flow of fluid material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This disclosure is a continuation of U.S. patent application Ser. No.16/293,448 filed on Mar. 5, 2019 which is a continuation-in-partapplication of U.S. patent application Ser. No. 15/817,245 filed on Nov.19, 2017 which claims priority to U.S. Provisional Patent Application62/424,444, filed on Nov. 19, 2016, all of which are hereby incorporatedby reference.

FIELD OF INVENTION

The present invention relates to the field of fluid transfer andtransportation systems, specifically pipelines, and methods to reducethe risk of leakage and resulting loss of transported material and/orenvironmental damage in the event of a breach of the pipeline.

BACKGROUND OF THE INVENTION

The statements in this section merely provide background informationrelated to the present disclosure. Accordingly, such statements are notintended to constitute an admission of prior art.

Many fluid materials, including petroleum and petroleum products, aretransported over long distances through pipelines. These pipelines crossover a variety of natural features, including features which could beseverely damaged in the event of spills resulting from breaches of thepipeline. These natural features include streams, lakes, expanses ofocean, bogs and marshes, aquifer watersheds, and others. In these areas,cleanup and remediation would be particularly difficult and expensive,and would likely be impossible to completely remediate.

Many of the pipeline sections crossing such sensitive areas are notmodified to reduce the risk of spills or to minimize the environmentaldamage that would result from such spills. Several incidents of damagingspills have occurred over the past several years, and a great deal ofconcern has been expressed about other areas in which the failure of apipeline would wreak potentially catastrophic environment damage.

A reliable, effective and economical method to prevent these spills atsensitive areas and/or to limit the environment damage is greatlyneeded. Likewise, a system is needed which can be applied to entirepipelines, or any section thereof.

SUMMARY

The system herein described is one which can provide the reduction ofspill hazards that is needed. Once deployed, it would provide a veryhigh level of assurance that a breach in a pipeline segment protected bythe deployed installation would not result in any substantialcontamination or environmental damage.

The invention includes several components, the most central andimportant of which is the provision of reduced or negative pressure inthe section of the pipeline to be protected. This reduced or negativepressure is provided by placing a pump on the downstream side of theportion of the pipeline to be protected, or the “crossing,” and arestriction to fluid flow on the upstream side of the crossing. In thepreferred embodiment, the pressure inside the pipeline in the crossingsegment will be lower than the ambient pressure. In most cases, thisreference ambient pressure will be the lowest expected atmosphericpressure at the location of the crossing.

When the pressure is lower than the ambient, a breach in the pipelinewill result in the ambient (water, air, muck in a bog, etc.) Being drawninto the pipeline, rather than the pipeline contents being expelled intothe ambient. The transported material will not be discharged into theenvironment in the protected section; rather, the material in theprotected section will be drawn into the pipeline, contaminating thetransported material, but not the environment.

Several optional but highly desirable features are provided. First, avalve can be provided on the upstream side of the crossing to allow theflow of material to be shut off in the event of a breach in theprotected section of the pipeline. In the preferred embodiment, thiswill be a differential-pressure actuated valve, installed upstream ofthe restrictor, which responds to the pressure change that will resultfrom a pipeline breach downstream of the restrictor. When so equipped,the system can be applied to pipelines transporting gaseous materials,and while it will not Be possible to eliminate the discharge of thegaseous contents of the pipeline section downstream of thedifferential-pressure actuated valve and upstream of the nearest checkvalve, the flow would be automatically shut off, preventing materialother than that present in pipeline between the valve and the nearestdownstream check valve rom being released. When an automatic valve suchas a differential-pressure actuated valve is installed in aliquids-carrying pipeline, it is desirable to provide a Fluid capacitoror accumulator upstream of the valve, so as to prevent pressure spikesupstream that would result from valve closure. This accumulator orcapacitor may be of various designs, including a simple standpipe ofadequate diameter and sufficiently tall to provide head pressuresufficient to overcome the incoming pressure in the pipeline, or aclosed vessel in which the compression of air of other gas will providethe countervailing pressure. The specifics of this fluid capacitor willbe engineered for each application to account for all of the variables,including, but not limited to, the pipeline size, velocity of thematerial being transported, viscosity of the material being transported,the elevations of the terrain over which the pipeline is constructed andthe elevations of the protected segment.

Another desirable feature is a tank containing a purging solution thatcan be used to purge oil or other transported materials from theprotected crossing after valve closure. Alternatively, a connection canbe provided to allow the introduction of purging solution transported tothe site when needed.

Yet another desirable feature is a tank on the downstream side of thecrossing, downstream of the pump, to which transported materialcontaminated by ambient materials drawn into the pipeline through abreach can be directed for storage and later recovery or disposition,preventing contaminated material from being carried on downstream,possibly compromising downstream equipment and facilities, such asrefineries. This tank would be isolated by a normally closed valveleading to the tank, and a normally open valve in the pipelinedownstream of the intersection providing the connection to the tank. Inthe event of a breach, and subsequent closure of the valve on theupstream side of the crossing, the normally closed valve would be openedto allow material to be pumped into the tank, while the normally openvalve would be closed to prevent further transport of materialdownstream.

A petroleum pipeline safety system for preventing contamination of anenvironmentally sensitive area close to a pipeline includes an upstreamportion of the pipeline supplying a flow of fluid material, a crossingportion of the pipeline receiving the flow of fluid material from theupstream portion and conveying the flow of fluid material through theenvironmentally sensitive area to a downstream portion of the pipeline,the downstream portion, a pipeline pressure activated valve selectivelycapable of blocking the flow of fluid material from entering thecrossing portion based upon a change in pressure within the crossingportion, and a fluid capacitor connected to the upstream portionconfigured to filter out a pressure spike in the upstream portionassociated with the valve blocking the flow of fluid material.

The petroleum pipeline safety system can include a fluid capacitorconfigured to stabilize the pressure within the pipeline to stabilizeoperation of the pipeline pressure activated valve. Further, thepipeline pressure activated valve can include any of a differentialpressure actuated valve, an electrically actuated valve, a hydraulicallyactuated valve, and a pneumatically actuated valve. Further, the systemcan include a flow restrictor downstream of the pipeline pressureactivated valve and upstream of the crossing portion of the pipeline,wherein the flow restrictor is configured to create a lower pipelineinternal pressure within the crossing portion as compared to a pipelineinternal pressure within the upstream portion. The flow restrictor canbe further configured to create the lower pipeline internal pressurewithin the crossing portion at a pressure lower than ambient atmosphere.The system can include, on the upstream side of the crossing portion anddownstream of the valve, either a purging solution tank configured torelease a purging solution into the crossing portion when the pipelinepressure activated valve blocks the flow of fluid material or aconnection through which a purging solution may be introduced into thecrossing portion. The system may also include, on the downstream side ofthe crossing portion and the pump, a contaminated material tankconfigured to receive a flow of contaminated material when the pipelinepressure activated valve blocks the flow of fluid material. The systemcan include a redundant pumping station configured to pump stationaryfluid material from the crossing portion, for example, when the pipelinepressure activated valve is closed. The pumping station can include anelectrical power generator. This emergency or backup electrical powergenerator may be installed to provide backup power to the primary pumpas well, in the event of an electrical power failure. The fluidcapacitor can include a closed top and an air portion trapped within thefluid capacitor, an open top and an air portion that can flow in and outof the fluid capacitor through the open top. An open top capacitor caninclude a floating ball check valve to prevent the flow of fluidmaterial from flowing out of the open top. The fluid capacitor can beconnected in-line with the pipeline. The system can further include apurging solution tank and a differential pressure actuated valveconfigured to release a purging solution from the purging solution tankinto the crossing portion when the pipeline pressure activated valveblocks the flow of fluid material.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show moreclearly how it may be carried into effect, reference will now be made,by way of example, to the accompanying drawings, which show an exemplaryembodiment of the present invention, and in which:

FIG. 1 is a plan view of the facility on the upstream side of thecrossing, in accordance with the present disclosure;

FIG. 2 is a plan view of the facility on the downstream side of thecrossing, in accordance with the present disclosure;

FIG. 3 is a perspective view of the facility on the upstream side of thecrossing of FIG. 1, in accordance with the present disclosure;

FIG. 4 is a perspective view of the facility on the downstream side ofthe crossing of FIG. 2, in accordance with the present disclosure;

FIG. 5 illustrates an exemplary embodiment of a fluid capacitor whichcan be used with the pipeline of FIG. 1, in accordance with the presentdisclosure;

FIG. 6 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1, in accordancewith the present disclosure;

FIG. 7 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1, in accordancewith the present disclosure; and

FIG. 8 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1, in accordancewith the present disclosure.

DETAILED DESCRIPTION

As required, detailed embodiments of the present invention are disclosedherein. However, it is to be understood that the disclosed embodimentsare exemplary only, and the invention may be embodied in various forms,especially so as to provide optimal performance in various environmentsand applications. The accompanying drawings are not intended to be toscale, and features may be exaggerated or minimized in order to bestdepict the system herein described. Therefore, the details disclosedherein are not to be interpreted as limiting, but merely as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention.

Referring now to the drawings, wherein the numerals refer to the variousfeatures of the system, composed of various parts that comprise thewhole.

As disclosed in this patent application, the system is comprised of anupstream and a downstream portion of the system.

The upstream portion is comprised of a restrictor, functioning torestrict flow so that the pump located on the downstream side of thecrossing creates a lower, or negative pressure in the crossing portionof the pipeline. In the preferred embodiment, the upstream portion alsoincludes a valve for shutting off flow in the event of a breach in thepipeline in the crossing section, and a fluid capacitor, or accumulator,upstream of the valve to prevent sudden pressure spikes upstream of thefacility upon valve closure. Other features may include a connectionthrough which a purging solution may introduced into the crossingsection of the pipeline in order to evacuate transported materialremaining in the crossing section of the pipeline alter valve closure sothat there is minimal contamination resulting from the breach or therepairs of such breach. This connection may include a tank to keeppurging materials present at all times, or can be used to introducepurging solution brought to the site as needed.

The downstream portion is comprised of a pump which draws transportedmaterial through the crossing section of the pipeline downstream of therestrictor. This downstream portion may include other features, such asa redundant pump that can be automatically engaged in the event of anyfailure of the primary pump, a generator system that may automaticallystart in the event of a power failure, and a tank for collectingpotentially contaminated transported material to prevent compromise ofdownstream facilities.

FIGS. 1-4 illustrate an exemplary embodiment of the disclosed petroleumpipeline safety system. Pipeline 1 leads into optional fluid capacitor2, or fluid accumulator, and then from fluid capacitor 2, to optionalvalve 3. Restrictor 4, is located downstream of the valve, when a valveis used. Whenever the valve is used and is a differential-pressureactuated valve, reduced-pressure supply tube 5, is installed betweenvalve 3, and pipeline 1A, downstream of restrictor 4, through connection11, in order to provide the lower pressure used to hold valve 3, in theopen position. As shown, provision is made for introducing a purgingsolution into pipeline 1A, downstream of restrictor 4, through accesspipe 6, connected to pipeline 1A, through connector 13, and providedwith valve 8, which is normally closed. As shown, tank 7, is providedfor holding a purging solution, but can be replaced with a connector forreceiving purging solution transported to the site as needed. From thisfacility, pipeline 1A, proceeds into and across the crossing, orprotected section of pipeline, 10.

Pipeline 1A, proceeds from crossing 10, to pump 12, and then downstreamthrough pipeline 1B. As shown, there is optional holding tank 15,connected to pipeline 1B, through connector 13, and connection pipe 6A,through normally closed valve 14. When this tank is provided, secondvalve 16, normally open, is provided to shut off flow to pipeline 17,proceeding downstream of the downstream facility.

FIG. 5 illustrates an exemplary embodiment of a fluid capacitor whichcan be used with the pipeline of FIG. 1. Fluid capacitor 102 isillustrated, including capacitor supply tube 104 and capacitor column106. Supply tube 104 is illustrated tapping from a neighboring pipeline.Capacitor column 106 includes a hollow interior which is filled in partwith an oil portion 108 and an air portion 110. Capacitor column 106includes open top 114. When pressure within supply tube 104 increases ordecreases, the height of oil portion 108 within capacitor column 106changes. Open top 114 permits air from air portion 110 to move in or outof column 106 when the height of oil portion 108 changes, the air withinair portion 110 remaining at ambient pressure. Open top 114 includesoptional cap 112 keeping rain and other contaminants from enteringcolumn 106.

Electronic capacitors are well known in the art and are used to filterout voltage spikes. Electronic capacitors include separated metallicplates and are known to resist changes in voltage, the changes involtage taking time to charge the plates. Such resistance to changes involtage can be used to filter the voltage, protecting the attachedcircuit from voltage spikes.

Pipelines are subject to pressure spikes, in particular, in relation toa sudden closing of a valve. Oil is a heavy fluid, and an entirepipeline of flowing oil can include substantial momentum. Sudden closureof a valve can cause all flow of oil to come to a sudden halt at thevalve, thereby resulting in a significant pressure spike. Such pressurespikes can be destructive, exceeding the maximum pressure rating for thepipeline or attached equipment. Fluid capacitors as disclosed herein canfilter out or resist sharp changes in pressure within the attachedpipeline. In relation to fluid capacitor 102 of FIG. 5, changes in oilpressure or fluid pressure within supply tube 104 cause changes inheight of oil portion 108. The resulting change in head pressure withincapacitor column 106 acts to resist changes in the oil pressure withinsupply tube 104, thereby filtering out sharp spike in oil pressure.

FIG. 6 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1. Fluid capacitor202 is illustrated, including capacitor supply tube 204 and capacitorcolumn 206. Supply tube 204 is illustrated tapping from a neighboringpipeline. Capacitor column 206 includes a hollow interior which isfilled in part with an oil portion 208 and an air portion 210. Capacitorcolumn 206 includes closed top 212. Changes in oil pressure withinsupply tube 204 cause a change in height of oil portion 208. Becauseclosed top 212 does not allow air from air portion 210 to escape, thechange in height of oil portion 208 results in a change in air pressurewithin air portion 210. By permitting oil portion 208 to change inheight, pressure spikes within supply 204 can be filtered.

FIG. 7 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1. Fluid capacitor302 is illustrated, including first pipeline portion 304, capacitorcolumn 306, and second pipeline portion 305. Fluid capacitor 302 isillustrated mounted to the illustrated pipeline portions as an in-linecomponent. As an in-line component, in some embodiments, fluid capacitor302 can react more quickly to changes in pipeline pressure than fluidcapacitor 102 of FIG. 5. Capacitor column 306 includes a hollow interiorwhich is filled in part with an oil portion 308 and an air portion 310.Capacitor column 306 includes open top 314. When pressure withinpipeline portions 304 and 305 increase or decrease, the height of oilportion 308 within capacitor column 306 changes. Open top 314 permitsair from air portion 310 to move in or out of column 306 when the heightof oil portion 308 changes, the air within air portion 310 remaining atambient pressure. Open top 314 includes optional cap 312 keeping rainand other contaminants from entering column 306. Fluid capacitor 302 isillustrated including an optional floating ball 320 within column 306and a mating cap valve 322 within column 306. Air from air portion 310can move past a hole in mating cap valve 322 and through neighboringopen top 314. As fluid enters column 306 and the fluid level rises,floating ball 320 can engage with mating cap valve 322, block the holein mating cap valve 322, and stop fluid from exiting the open top 314 offluid capacitor 302. Floating ball 320 and mating cap valve 322 cancollectively be described as a floating ball check valve within fluidcapacitor 302.

FIG. 8 illustrates an additional exemplary embodiment of a fluidcapacitor which can be used with the pipeline of FIG. 1. Fluid capacitor402 is illustrated, including first pipeline portion 404, capacitorcolumn 406, and second pipeline portion 405. Fluid capacitor 402 isillustrated mounted to the illustrated pipeline portions as an in-linecomponent. As an in-line component, in some embodiments, fluid capacitor402 can react more quickly to changes in pipeline pressure than fluidcapacitor 402 of FIG. 6. Capacitor column 406 includes a hollow interiorwhich is filled in part with an oil portion 408 and an air portion 410.Capacitor column 406 includes closed top 412. Changes in oil pressurewithin pipeline portions 404 and 405 cause a change in height of oilportion 408. Because closed top 412 does not allow air from air portion410 to escape, the change in height of oil portion 408 results in achange in air pressure within air portion 410. By permitting oil portion408 to change in height, pressure spikes within supply 404 can befiltered.

Illustrated fluid capacitors can include different dimensions,proportions, and specific designs. The illustrated fluid capacitors areexemplary, and are not intended to be limiting to the disclosure.

The disclosed pipeline can include a valve that shuts automaticallybased upon changes in pressure within the pipeline. It will beappreciated that such a valve should be sensitive enough to catchsignificant leaks in the pipeline, for example, including changes ofpressure in the pipeline without the pipeline being completely severed.However, the closing of the valve can be a significant event, forexample, which can result in depriving a refinery of oil and requiringan operator to go to the valve and reset it. The valve can include atuning mechanism for example, including an adjustable feedback loopwithin the pipeline, which can be used to filter out brief,insignificant changes in oil pressure while causing the required valveactuation for an actual failure of the pipeline. Such a filtering of thefeedback pressure to the valve can include a fluid capacitor, such asthe fluid capacitors described herein, to filter out momentaryfluctuations in pressure.

A number of pipeline pressure activated valves can be used to stop aflow of oil, refined fuel, or other fluid materials through a pipelineto protect an environmentally sensitive area close to the pipeline. Inone embodiment, the valve can be electrically activated, with pressuresensors within or attached to the pipeline providing a monitored valueor values for use to control the valve. Similarly, a hydraulically orpneumatically controlled valve can similarly be utilized to control flowthrough the pipeline. In another embodiment a differential pressureactuated valve can be utilized, wherein no outside electrical or otherpower source is required. In such a valve, pressure from within theattached pipeline is used to maintain the valve in an open state, andwhen the pressure changes past a calibrated pressure value, the valvecloses by action of the pipeline pressure acting upon the valve. Anexemplary embodiment of a differential pressure actuated valve isdisclosed in co-pending U.S. patent application Ser. No. 15/817,244filed on Nov. 19, 2017, which is hereby incorporated by reference.

When a device or structure is said to be upstream of a portion of thepipeline, the device or structure is located or attached to the pipelineat a point from which the flow of fluid material flows toward thedirection of the portion of the pipeline in question. When a device orstructure is said to be downstream of a portion of the pipeline, thedevice or structure is located or attached to the pipeline at a pointfrom to which the flow of fluid material flows from the portion of thepipeline in question.

The disclosure has described certain preferred embodiments andmodifications of those embodiments. Further modifications andalterations may occur to others upon reading and understanding thespecification. Therefore, it is intended that the disclosure not belimited to the particular embodiment(s) disclosed as the best modecontemplated for carrying out this disclosure, but that the disclosurewill include all embodiments falling within the scope of the appendedclaims.

The invention claimed is:
 1. A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline, the system comprising: a first portion of the pipeline including an upstream portion of the pipeline supplying a flow of fluid material; a second portion of the pipeline including a crossing portion of the pipeline, receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline; a third portion of the pipeline including the downstream portion of the pipeline; a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion; a flow restrictor downstream of the pipeline pressure activated valve and upstream of the crossing portion of the pipeline, wherein the flow restrictor is configured to create a lower pipeline internal pressure within the crossing portion as compared to a pipeline internal pressure within the upstream portion; a reduced-pressure supply tube including a first end and a second end and connected at the first end to the crossing portion of the pipeline and connected at the second end to the pipeline pressure activated valve, wherein reduced-pressure supply tube is configured to supply the lower pipeline internal pressure created by the flow restrictor to the pipeline pressure activated valve and wherein the pipeline pressure activated valve is a differential pressure actuated valve and is configured to be selectively held in an open position based upon the lower pipeline internal pressure; and a pump downstream of the crossing portion of the pipeline.
 2. The petroleum pipeline safety system of claim 1, further comprising a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the pipeline pressure activated valve blocking the flow of fluid material.
 3. The petroleum pipeline safety system of claim 2, wherein the fluid capacitor is configured to stabilize the pressure within the pipeline to stabilize operation of the pipeline pressure activated valve.
 4. The petroleum pipeline safety system of claim 2, wherein the fluid capacitor comprises a closed top and an air portion trapped within the fluid capacitor.
 5. The petroleum pipeline safety system of claim 2, wherein the fluid capacitor is connected in-line with the pipeline.
 6. The petroleum pipeline safety system of claim 1, wherein the flow restrictor is further configured to create the lower pipeline internal pressure within the crossing portion at a pressure lower than ambient atmosphere.
 7. The petroleum pipeline safety system of claim 1, further comprising a purging solution tank configured to release a purging solution into the crossing portion when the pipeline pressure activated valve blocks the flow of fluid material.
 8. The petroleum pipeline safety system of claim 1, further comprising a redundant pumping station configured to pump stationary fluid material from the crossing portion.
 9. The petroleum pipeline safety system of claim 8, further comprising an electrical power generator attached to the redundant pumping station.
 10. The petroleum pipeline safety system of claim 1, further comprising: a purging solution tank; and a differential pressure actuated valve configured to release a purging solution from the purging solution tank into the crossing portion when the pipeline pressure activated valve blocks the flow of fluid material.
 11. A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline, the system comprising: a first portion of the pipeline including an upstream portion of the pipeline supplying a flow of fluid material; a second portion of the pipeline including a crossing portion of the pipeline, receiving the flow of fluid material from the upstream portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline; a third portion of the pipeline including the downstream portion of the pipeline; a pipeline pressure activated valve selectively capable of blocking the flow of fluid material from entering the crossing portion based upon a change in pressure within the crossing portion; a fluid capacitor connected to the upstream portion configured to filter out a pressure spike in the upstream portion associated with the pipeline pressure activated valve blocking the flow of fluid material, wherein the fluid capacitor is connected in-line with the pipeline; a flow restrictor downstream of the pipeline pressure activated valve and upstream of the crossing portion of the pipeline, wherein the flow restrictor is configured to create a lower pipeline internal pressure within the crossing portion as compared to a pipeline internal pressure within the upstream portion and at a pressure lower than ambient atmosphere; a reduced-pressure supply tube including a first end and a second end and connected at the first end to the crossing portion of the pipeline and connected at the second end to the pipeline pressure activated valve, wherein reduced-pressure supply tube is configured to supply the lower pipeline internal pressure created by the flow restrictor to the pipeline pressure activated valve and wherein the pipeline pressure activated valve is a differential pressure actuated valve and is configured to be selectively held in an open position based upon the lower pipeline internal pressure; and a pump downstream of the crossing portion of the pipeline.
 12. The petroleum pipeline safety system of claim 11, further comprising: a purging solution tank configured to release a purging solution into the crossing portion when the pipeline pressure activated valve blocks the flow of fluid material. 